A portable terminal 101 as shown in FIG. 7 has been known, in which a display unit cabinet 103 that houses a display unit 102 such as a liquid crystal display is reinforced with a reinforcing frame 103a. This reinforcing frame 103a separates, from the display unit 102, a main substrate 107 and a rechargeable battery 106 that are provided near the backside, thereby protecting the display unit 102. It is recommended that the reinforcing frame 103a have a flat surface to prevent the display unit 102 from having a faint mark which looks like as if something was blotting. To meet a recently increasing demand for reduction in the thickness of the portable terminal 101 such as a mobile telephone, according to a technique, the reinforcing frame 103a is formed out of a sheet metal such as a stainless steel sheet. As shown in FIG. 7, flexible substrates 102d and 102e that extend from the display unit 102 and function as signal conductors need to be bent back and connected to the main substrate 107 through a signal conductor through hole 103c. 
As a component for increasing the strength of a sheet metal portion, a shielding case described in Patent Document 1 has been known, for example. This shielding case has a recess formed by inwardly recessing its outer surface such that the recess comes into contact with, or close to, an electronic component. This recess is filled with a resin material, thereby making the outer surface substantially flat.